Free-fall simulator capable of displaying a simulated visual environment

ABSTRACT

A simulator of free-fall containing air power generators ( 1 ) and appreciably cylindrical aerodynamic vein ( 2 ), in which evolve the persons ( 6 ) in state of free-fall, the wall ( 24 ) of which is realized by means of a film of flexible material stretched only by means of two frames ( 28 ) ( 29 ) fixed at the extremities of the aerodynamic vein ( 2 ) and to the superstructure ( 5 ) maintaining the aerodynamic vein ( 2 ). In particular the film of flexible material forming the wall ( 24 ) of the aerodynamic vein ( 2 ) is translucent and serves as screen to display from the outside of the vein ( 2 ) real or simulated images intended to be seen from inside of the aforementioned vein ( 2 ). In a particular mode of realization the air power generators ( 1 ) are arranged in a container for transport ( 74 ) and the superstructure ( 5 ) of the simulator can be disassembled so that the simulator is easily transported.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No. PCT/FR2006/050822, International Filing Date, Aug. 29, 2006, which designated the United States of America, and which international application was published under PCT Article 21(2) as WO Publication No. WO 2007/026100 A1 and which claims priority from French Application No. 0552606, filed Aug. 30, 2005, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

The disclosed embodiments concern a device simulating free-fall such as experienced by parachutists by means of a vertical blower, i.e. means intended to maintain appreciably still at least one person in position of free-fall in a flow of vertically ascending air. More specifically the disclosed embodiments concern a simulator of free-fall with means of displaying an outside visual environment generated during the simulated free-fall.

2. Brief Description

The free-fall training for parachutists to learn and improve the movements and the positions that must be taken during the free-fall phases has shown for a long time the need for economical and reliable means to enable learning and the training during any season, independently from weather conditions required for jumping from a plane,.

Relatively simple methods have been designed using rubber bands by which the parachutist is suspended by his/her body and his/her limbs not touching the ground. This elastic strings allow the parachutists to be put in characteristic conditions of the fall ensuring the separation from the ground in an attitude close to that of the free-fall while preserving the possibility to make movements notably under the leadership or the control from an instructor.

Such methods, while economical, are however very far from being representative of the reality of the physical phenomena met during the free-fall and do not allow the parachutist to feel the effects of the fall nor allow him/her to train correctly for the control of the position during the fall.

The vertical blowers used in research centres for aerodynamics inspired the designers of free-fall simulators. In spite of their relatively high cost, these vertical blowers allow, when their power is sufficient, to insure the still position of a parachutist in condition of free-fall in a vein of vertical aerodynamic flow in which the air passes from the bottom upward the vein and with speeds compatible with the maintaining of the parachutist in stable vertical position, typically 40 m/s to 70 m/s.

Various vertical blowers of this type for simulators of fall were conceived with characteristics varying in accordance to the objectives of their designers. Therefore, some of these blowers are of a diameter and a power sufficient to enable the simulation of fall for two or three parachutists simultaneously with the aim of training for figures realized during the jump competitions.

Examples of such simulators of free-falls are found in patents U.S. Pat. No. 3,484,953 or GB 2094162. These two patents present simulators of free-falls designed following the principle of blowers with closed aerodynamic veins in which the air, accelerated in the vein of the blower where evolve one or several parachutists, follows a closed loop passing by the exit of the aforementioned vein and its introduction in the same vein after crossing one or several helixes which generate the aerodynamic flow. In these designs, the infrastructures of blowers are for example made of concrete and are fixed installations due to their dimensions and their masses.

To equip with lower costs the centres of parachuting and also to create simulators of free-falls intended for the discovery by the public of the sensations of free-fall in fairs and other places of animation, free-falls simulators of lighter construction and or transportable have been envisioned.

Examples of such realizations are given in the patent GB 2062557, which implements an architecture of a blower with a looping aerodynamic vein as in the examples quoted previously, or in the application for a patent WO 83/01380 which works with an opened aerodynamic vein, that is in which the air entering the vein is taken from the surrounding volume and ejected at the top of the simulator to the surrounding volume.

All these simulators present means more or less elaborated to reach the trial vein but, apart from protection nets or padding of the walls of the aerodynamic vein in which parachutists evolve during the training, they do not intrinsically assure the safety of the persons realizing a simulated jump.

In the patent application WO 83/01380 already quoted, the walls of the aerodynamic vein are made of a flexible material such as a cloth or a sheet of a transparent material, but stiff structures are arranged near the flexible walls of the aerodynamic vein to which these walls are connected by maintaining sails. This arrangement of the aerodynamic vein and its maintaining does not guarantee that the person evolving in state of free-fall will not strike a stiff structure in case of shock against the wall of the flexible aerodynamic vein, and even less in case of failure of the flexible wall, for example a tear.

In spite of the personal protections that are used, notably helmets and special overalls, incidents and accidents are not uncommon during the use of all these types of fall simulators, even with persons who regularly practise free-fall.

To improve still the realism of the simulation, methods of visual display of the environment during the jump were proposed in association to some of these vertical blowers used as simulators of free-falls. The U.S. Pat. No. 5,655,909 suggests simulating the visual environment of the parachutist by means of screens on at least a part of the aerodynamic vein in which the parachutist evolves when he executes a simulated jump. The proposed solution consists of replacing a part of the wall of the vein by a device displaying images over multiple screens, a device sometimes called an image wall. This type of device enables to generate images on relatively large surfaces but presents the inconvenience to show an image with missing parts like at the edges of screens, to be very heavy and voluminous thus of a difficult installation and also to place on the wall of the aerodynamic vein stiff structures, notably screens and their necessary supports. The consequences, if the person evolving in the aerodynamic vein strikes the wall of the aforementioned vein, are aggravated in that case by the fact that the system of visual display of the environment makes almost impossible the padding of the vein walls.

SUMMARY

The disclosed embodiments propose a jump simulator that is easy to install and to operate, which offers maximum safety to the users and which architecture allows them to enjoy a visual display of the projected environment over 360 degrees during the simulated free-fall.

More particularly, the free-fall simulator in these disclosed embodiments contains powerful air generation devices to create an air stream with a speed compatible with the preservation in a state of free-fall of at least one person in an aerodynamic vein of appreciably vertical axis constituted by a film of flexible, resistant and not elastic material, such as a canvas shaped as a tube only fixed to two frames positioned at the extremities of the tube, the film of flexible material constituting the vein being stretched out in the longitudinal direction of the tube by only a supporting superstructure to which the frames are fixed.

Preferably the wall of the aerodynamic vein is made of a single panel of the flexible film wrapped around and closed by a fixation line to form the tube of the aerodynamic vein.

Advantageously the aforementioned superstructure is of dimensions such that the flexible wall of the aerodynamic vein is far away enough from any stiff element of the superstructure so that the person in state of simulated fall cannot strike a stiff element in case of loss of control of position in the aerodynamic vein.

In a particular mode of realization of the disclosed embodiments the air generators means contain at least one engine situated preferably in a separate chamber, at least one helix and a rectifier-diffuser.

Advantageously the rectifier-diffuser is situated at the top of the chamber containing at least one engine and the superstructure keeps the aerodynamic vein vertically above it and appreciably in the axis of the rectifier diffuser.

In a particular mode of realization of the disclosed embodiments, the air that must be accelerated in the aerodynamic vein penetrates into a chamber containing at least an engine by at least an opening realized in a wall of the chamber.

For transport convenience and simplification of the assembly and/or disassembly operations of the simulator, the power air generators are advantageously installed in a permanent way in all or part of a transport container.

In a particular shape of the disclosed embodiments, the film of flexible material constituting the wall of the aerodynamic vein is translucent and allows, serving as screen, the projection from the outside of the vein of images visible from inside the vein. Advantageously images which can simulate the visual effect of the free-fall are projected by at least one projector situated outside of the vein or by several projectors enabling the coverage of 360 degree field of vision in a horizontal plane. Projectors are advantageously fixed to the superstructure maintaining the aerodynamic vein.

In a particular mode of application of the simulator, the projected images include the real time image of at least one person filmed in state of free-fall in another free-fall simulator.

In a particular mode of realization, the aerodynamic vein and the other elements of the simulator of free-fall are protected from bad weather, and possibly from the excessive light affecting the conditions necessary for a good contrast of the projected images, by means of a cover such as a tarp and or panels, which elements take advantageously support on the superstructure maintaining the aerodynamic vein while preserving the conditions of opening or air tightness necessary to the correct aerodynamic operation of the simulator.

Means of control and command are foreseen to watch the operation of the simulator of free-fall and the evolutions of the person in a state of free-fall as well as to act on the operation of the simulator.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of a type of realization of the disclosed embodiments is provided in reference to the corresponding figures:

FIGS. 1: overview of a mode of realization of a simulator according to the disclosed embodiments and its main constituents;

FIG. 2: view of the air power generators means and cut-away diagram of the chamber containing an engine;

FIG. 3: view in perspective of an aerodynamic vein according to the disclosed embodiments and the means of projection of images on the wall of the aerodynamic vein;

FIG. 4: view of a superstructure maintaining the aerodynamic vein and the devices for outside protection;

FIG. 5: illustration of the devices associated with the simulator of free-fail. The detail a) presents an example of an apparatus for control and surveillance of the simulator.

DETAILED DESCRIPTION

The simulator of free-fall following the disclosed embodiments contains air power generators 1 capable of ensuring the acceleration of the air in an aerodynamic vein, an aerodynamic vein 2 of dimensions adapted to the evolutions of at least one person 6 in a situation of free-fall, devices 3 to generate real images or a simulated outside visual environment for the person evolving in the aerodynamic vein, the means 4 of piloting and controlling the blower and the devices for images generation, a superstructure 5 capable of maintaining these various means and possible accessory devices as well as supporting means of protection from the outside environment.

These various apparatuses are either assembled with the objective to obtain a fixed installation of the simulator of free-fall, or are conceived for a simplified assembly and disassembly to realize a movable installation.

In this last case, these means and the aforementioned superstructure are designed to ensure the transportability of the whole simulator for example in one or several containers, the dimensions of which are compatible with the traditional means of road, rail, sea or air transport.

The example of detailed description of a simulator of free-fall according to the disclosed embodiments given above corresponds essentially to the case of a simulator of free-fall having the capacity to be easily transported for a simplified delivery and start of operation either for an itinerant use to allow the biggest number of persons to experience free-fall in parachuting clubs or public exhibitions.

The air power generators means 1 contain at least an engine 10 the power of which is calculated according to the average section 23 of the aerodynamic vein 2 and the expected speed of the vertical flow of air in the vein. This engine or these engines 10 which are electric or thermal, drive, if needed through speed reducers and or through angle connecters, not represented, one or several helixes 11 the characteristics of which are also derived from the characteristics of the aerodynamic vein 2 and the characteristics of the expected aerodynamic flow. The determination of the required total power and the detailed characteristics of one or several helixes results from the calculation of aerodynamic blowers known to the persons skilled in the art. For a bigger autonomy of the simulator of free-fall, it is preferable to use one or several thermal engines, for example engines of Diesel type, capable of supplying powers of the order of 1000 KW that are necessary to drive one or several helixes 11 of the blower for the simulator of this disclosed embodiments. The number of helixes 11 and engines 10 is selected according to the average section 23 of the aerodynamic vein 2 and the power of the available engines. Economic criteria can also lead to select a bigger number of less powerful engines for example.

The one or several engines 10 of the air power generators are installed in a chamber 12, which is conceived to receive in its top part 13 the aerodynamic vein 2. The one or several helixes 11 is or are mounted with their axes of rotation 14 appreciably vertical to generate an air stream 15 directed upwards. Advantageously the so accelerated air 15 is exiting the chamber 12 where are located one or several engines 10 which improves the cooling of all the engines 10 and the eventual speed reducers.

At least an opening 17 is foreseen in the wall of the chamber 12 to allow the arrival of the air 18 indispensable to the operation of the aerodynamic vein 2. In case of use of one or several thermal engines, one or several fuel reservoirs 70 are foreseen to insure the autonomy wished for the blower. These reservoirs 70 and the input and output fuel pipes are realized according to state of the art and to the safety standards in effect. For example, if the simulator is itinerant, the reserve of fuel is split in several reservoirs 70 not to exceed a 500 liter volume by reservoir, maximum allowed by certain standards for mobile installations, and one or several reservoirs 70 are preferably isolated from one or several engines 10 to limit the risks in case of fire. In particular means for the safety and protection against the fire (not represented on figures) are installed in as much quantity as required in the chamber 12 of one or several engines.

Above the one or several helixes 11 is a rectifier-diffuser 19. This rectifier-diffuser 19 is intended to stabilize the aerodynamic flow 15 accelerated by the one or several helixes 11 which is particularly turbulent after its passage through one or several helixes. In a classic way this rectifier-diffuser 19 is realized with a grid made of thin walls of a sufficient length so that the flow is stabilized during its crossing.

To facilitate its transport, the chamber 1 packaging one or several engines 10, one or several helixes 11, possibly the rectifier-diffuser 19 and possibly fuel tanks 70 in the case of the use of thermal engines are advantageously installed in one or several containers with a size adequate for road, railway, maritime or air transports. Preferably, this container is or these containers are capable of receiving elements from the other parts of the simulator, after their disassembly, to facilitate the transport of the free fall simulator.

In a container of traditional dimensions, approximately 3 metres in width, 12 metres in length and 2.6 metres in height, it is so possible to realize a chamber 1 approximately 4 metres in length and of the width of the container, sufficient to contain one or several engines 10, one or several helixes 11 and the rectifier-diffuser 19. The remaining space, approximately 8 metres over the length of the container, allows the installation or storage during the transport of the other elements associated with the simulator.

Above the one or several helixes 11 and above this rectifier-diffuser 19, in the continuation of these, is installed the aerodynamic vein 2 of vertical axis 20 in which evolve one or several persons 6 in position of free-fall. This vein 2 corresponds to a tube of appreciably vertical axis, having a lower extremity 21 and a upper extremity 22 and preferably appreciably cylindrical or slightly conically flared out upwards. In the latter and favourite mode of realization the upper section extremity 22 is bigger than that of the lower extremity 21 to create in the aerodynamic vein 2 a negative pressure gradient of speed from bottom upwards, the effect of which pressure gradient is favourable to the stability of the vertical position in the vein 2 of the person 6 in state of free-fall. The average section 23 is preferably appreciably circular but other sections are possible, for example elliptic sections or polygonal sections. For an installation of the chamber 12 in a container sized for road transport, the transverse dimensions in the aerodynamic flow 15 of the low section 21 of the vein 2 are limited to approximately 3 metres. In that case the upper section 22 of the vein 2 is for example 3.6 metres in its transverse dimensions in the aerodynamic flow 15 and for example of the order of 4 metres in its useful height in the direction of the aerodynamic flow 15 between the lower 21 and upper 22 extremities.

These relatively modest dimensions for a simulator of fall have the advantage on one hand to facilitate the realization of a transportable blowing system and on the other to provide safety for the person 6 in situation of simulated fall. Indeed in the cases where the person 6 in situation of fall simulated in the vein does not ensure correctly the control of its position appreciably at the centre of the aerodynamic vein 2, frequent situation for untrained persons, this person 6 has, considering the distances for free fly in the aerodynamic vein 2, no time to acquire an important speed in regard to the wall 24 of the vein 2 and to the protections in its upper 25 and lower 26 extremities, even in case of important accelerations, and, therefore, the risk of wounds during a contact with the wall 24 or the protections 25, 26 is substantially decreased because of the weak relative speeds in regard to the wall and to these protections.

Another important characteristic of the aerodynamic vein 2 concerns its mode of realization. In the presented simulator of free-fall, the lateral wall 24 of the aerodynamic vein 2 in which evolve the persons 6 in state of free-fall is realized by means of a film of flexible material. This film, for example a cloth chosen for its resistance and the stability of its dimensions, is assembled to form a tube of which the length and the perimeter at the extremities correspond to those sought for the length of the aerodynamic vein 2 and the perimeters of its sections at extremities 21, 22. We can find today very resistant and non elastic cloth for the foreseen field of application suitable to the vein realization such as cloth made of synthetic fibres with materials such as polyester or aramide, for example Dacron® or Kevlar®, widely used for the aeronautical applications or for the manufacture of the sails for boats.

Preferably the tube forming the wall 24 of the aerodynamic vein 2 is realized by means of a panel, of the aforementioned film of flexible material, formed and closed on itself to bring edge to edge the opposite sides of the panel appreciably directed along one side of the tube parallel to its axis. The joining edges are assembled by means of a line of fixations 27 the resistance of which is at least the same level as that of the film of flexible material. So, when joining edges are not assembled, the panel of film of flexible material can be put back flat then rolled, for example on a cylindrical support, for its storage or transport, without creating folds that could damage the wall 24 or its appearance.

The fixations, not represented, are realized for example by means of zippers or of laces passing though eyelets or of material featuring hooks as Velcro® or by combinations of those means.

Preferably, on at least the bottom of the line of fixation 27, the means of fixation are chosen to allow a fast opening and closing of the wall 24 on a height sufficient to authorize the passage of the person 6 before or after a simulated jump.

Finally this film of flexible material is stretched out between two frames of extremity 28, 29 giving to this film of flexible material the shape expected for the extremities, respectively 21, 22, of the aerodynamic vein 2. These frames 28, 29 are realized by means of tubes or profiles made of metal or composite materials for example, of which the shape and the section are sufficient to guarantee the necessary rigidity and the resistance to stand the tension load of the film of flexible material, including during the operation of the simulator.

It is essential that no stiff structure be close to the wall 24, and even less in the inside of the aerodynamic vein 2. The build up of tension and the holding of the canvas constituting the wall 24 of the aerodynamic vein 2 between its two frames at the extremities 28, 29 is realized by connecting the aforementioned frames 28, 29 to the superstructure 5, the stiff elements of which are away from the wall 24 of the aerodynamic vein 2 and which ensures the preservation of the correct position of the frames of extremity 28, 29. The lower frame 28 is fixed above and around the exit of the diffuser 19 so as to force the flow of air 15 accelerated by one or several helixes 11 to penetrate into the aerodynamic vein 2. The top frame 29 is fixed to the top of the superstructure. Preferably, one at least both frames 28, 29 is fixed through tensioning devices, not represented, for example tensioning devices with screws or hydraulic tensioning devices, which facilitate the assembly of the aerodynamic vein 2 and apply to the film of flexible material the desired tension forces. In a particular mode of realization elastic devices, not represented, are inserted in series with the fixations of at least one of both frames to provide to the concerned frames the possibility of small motions in order to limit the efforts exerted on the film of flexible material in case of shock in the aerodynamic vein 2 during its use. This architecture of the aerodynamic vein 2 allows, besides its relatively easy assembly and disassembly, to limit the risks of serious wound to the person 6 evolving in state of free-fall in case of shocks against the wall 24 by avoiding any possibility of contact with a stiff structure. In the choice of the resistance of the film of flexible material are taken into account the forces applied to the aforementioned film by the potential shocks in addition to the forces of tension of the assembly and the forces in relation to the aerodynamic flows.

In a mode of realization of the disclosed embodiments, another important characteristic of the wall 24 of the aerodynamic vein 2 is its capacity to serve as a screen to display images. In that case the selected film of flexible material, besides its indispensable mechanical characteristics, is translucent so that images projected from the outside of the aerodynamic vein 2 on the outside face 35 of the aforementioned vein are visible in a satisfactory manner from the inside 36 of the wall 24 of the vein by the person 6 in state of free-fall.

Certain films of flexible materials realized from fibres of the synthetic materials already mentioned present sufficient characteristics of translucence, without excessive transparency or opaqueness, to ensure this screen function.

To project on the wall 24 of the aerodynamic vein 2 a representation of the visual environment during the simulated fall at least one projector 31 is positioned outside of the aerodynamic vein. The simulated environment is more or less sophisticated depending on the effect being sought. For example the projected image can represent:

An fix image of the horizon, or;

An image scrolling vertically fixed shapes, for example by means of a disc or of a drum having the motives to be projected and turning behind a projector lens, or;

The images of a film corresponding to those of real or imaginary free-falls, or;

Computer generated images calculated in real time according to the evolutions of the person in state of free-fall, or;

A combination of these images.

In the hypothesis of a use as an attraction for the public, it's better to present attractive images and thus preferably different from those effectively recorded during a real jump of free-fall at high altitude. For example it is possible to present images corresponding to an appreciably horizontal movement close to the ground to give to the person the impression of moving as a bird.

In a favourite mode of realization of the disclosed embodiments, at least three projectors are arranged around the aerodynamic vein to ensure a correct representation of the outside environment over 360° in a horizontal plane.

To improve the quality of the projected image, according to the number of projectors 31 and the distance between projectors 31 and wall 24 of the aerodynamic vein 2 serving as the screen, projectors 31 optionally dispose from means to correct the geometry of the images, such as anamorphic objectives 32 or images shaped before projection by electronic means 33 associates to projectors 31 in case of use of video projectors, to take into account the fact that the screen made by the wall 24 of the aerodynamic vein 2 is curved.

This arrangement of the means 3 of image projection, by placing said means 5 outside of the aerodynamic vein 2 and away from the wall 24 of the vein, prevents all risks of contact with hard objects during the evolutions of the person 6 in state of free-fall.

To ensure the tension of the film of flexible material constituting the aerodynamic vein 2 and the correct position of the aforementioned vein, a superstructure 5 is placed above the chamber 12 containing the air power generators 1. This superstructure ensures the location and the maintaining of the frames 28 and 29 placed at the extremities of the aerodynamic vein 2. Realized for example with tubes or profiles 51 in metal or in composite materials it is calculated to resist the longitudinal forces in the film of flexible material of the aerodynamic vein 2. All the parts of the superstructure 5 are far away enough from the flexible wall 24 of the aerodynamic vein 2 so that in no case a person 6 evolving in the vein 2 and who collides with the flexible wall 24 can get in contact with stiff parts of the superstructure 5 in spite of the deformations, inevitable but acceptable in these circumstances, of the wall 24 of the aerodynamic vein 2. By its dimensions this superstructure 5 takes into account the extreme case of a failure of the flexible wall 24 of the aerodynamic vein 2 and in addition the mattresses 52, for example filled up with foam material, are arranged if need be to protect particular zones against which the person 6 in state of free-fall could enter in contact.

In practice, it is recommended that the distance between the wall 24 of the aerodynamic vein 2 and the vertical mounts of the superstructure 5 be appreciably at least equal to the average diameter of the aerodynamic vein 2, or approximately 3 metres in the detailed example of realization described above for the disclosed embodiments.

Advantageously this superstructure 5 supports means 53 to protect the aerodynamic vein 2 and its associated parts 1, 3, 4 of the weather, the wind and the rain in particular, when the simulator of free-fall is not installed in a protected place such as inside a building. Besides these means of protection 53 or the other dedicated devices are capable of setting around the aerodynamic vein 2 an environment dark enough to guarantee sufficient contrast for the images projected on the translucent walls 24 of the vein 2 when the simulator of free-fall is equipped with the means 3 of representation of the outside visual environment. These means of protection 53 consist for example of more or less opaque panels fixed to the superstructure or tarp of the type used for the constructions of tents intended for the reception of the public and taking support on the superstructure 5 or on secondary structures (not represented).

For the operation as closed loop of the aerodynamic blower, these means of protection 53 taking support on the superstructure 5 also cover the chamber 12 in which are installed engines 10 or at least one or several openings 17 of the chamber 12 by which arrives the air 18 that is accelerated in the aerodynamic vein 2. In that case, the space 54 between the wall 24 of the aerodynamic vein 2 and the wall of these means of protection 53 serves as a buffer zone for the return of the air between the exit 22 of the vein and the openings 17 of the engines chamber. This space is thus also sized to have a sufficient cross section so that the flow of air circulating in the blower can be ensured without excessive pressure loss there. A receiver capable by his structure and by his shape to steer the air going out of the aerodynamic vein towards the sides and downwards around the aerodynamic vein 2 is arranged near the exit 22 of the vein, at its top.

For the operation as opened aerodynamic blower, these means of protection 53 ensure the protection of the aerodynamic vein 2 and its associated elements 1, 3, 4. In all cases these means of protection 53 are realized not to obstruct the arrival of the outside air towards one or several openings 17 of the chamber 12 of the engines. Above the aerodynamic vein 2, at the top of the means of protection 53, one or several openings are foreseen to let the air out of the aerodynamic vein 2 towards the outside. This or these openings are preferably covered by a receiver 56 to avoid that the rain or foreign bodies, and possibly the light, can penetrate into the protected zone from the aerodynamic vein 2 but without hindering the stream of air that must flow towards the outside.

In a particular mode of realization of the disclosed embodiments, the superstructure 5 is realized with sufficient dimensions so that projectors 31 associates to the system of representation of the visual environment 3 during the free-fall are fixed in a secure and stable way with respect to the aerodynamic vein 2. The dimensions of the superstructure 5 are compatible with the location of one or several projectors 31 at sufficient distance from the wall 21 of the aerodynamic vein 2 which serves as screen so that this or these projectors 31 operate in a satisfactory manner. The precise positioning and the stability of these projectors 31 are necessary so that the projected images are stable enough and ensure the quality of the rendering of the whole scene notably in the zones where the images projected by the various projectors 31 are connected, when several projectors 31 are used.

In a mode of realization the superstructure is constituted by a set of beams 51 equipped with connections 57 that can be disassembled, for example by bolts at their extremities (not represented), to ensure the possible assembly and disassembly of the free-fall simulator for its transport.

Other means necessary or useful for the operation, for the surveillance and for the control of the simulator of falls are associated to the simulator.

The simulator contains in particular at least a room of control and command 4 which allows from the cockpit 41 of the simulator to watch the parameters of the simulator and its equipments.

Among the parameters important to watch preferably, without this list being exhaustive, are:

The temperatures:

air of the blower;

cooling water;

oil in engines and gearings;

The powers and the rotation speed of the one or several engines or of the one or several axes of the one or several helixes;

The speed of the air flow in the aerodynamic vein.

The command parts include at least the means to pilot the power of the blower to act in particular on the speed of the air flow in the aerodynamic vein, which notably varies according to the weight of the person 6 to be maintained in state of simulated free-fall, and also contains the control of devices related to the security, such as the commands for emergency shutdown or related to the fire safety.

A subset of these means of command and control can be automated.

Preferably the simulator of free-fall also contains at least one camera of surveillance 42 permitting the observation of the person 6 in the aerodynamic vein 2 by means of at least a video monitor 43 near the checkpoint and command post. Such a camera 42 is placed outside the part of the vein 2 where the person 6 can evolve in state of free-fall, for example in the upper part, above a net of protection 25 which limits the usable space at the top of the aerodynamic vein, or in the lower part, below a net 26 which limits the usable lower space.

This camera 42 and or the other cameras associated or not, also serve if needed to record the evolutions of the person 6 in state of free-fall. The parachutist in training has then the possibility to review the simulated jump and analyze the defects and the corrections to the positions that must be undertaken. For the recreational applications the persons having gone through a free-fall simulation have the possibility to keep a video recording of their free-fall experience.

In a mode of use whereby two or several simulators of free-fall operate in a coordinated way, on the same site or on distant sites, the images of the person 6 in a state of free-fall in one simulator can be transmitted in real time to the means 3 of representation of the simulated visual environment of one or several other simulators working in a coordinated way, so that the aforementioned images are inserted into the images projected in this or these other simulators. In this way the impression from jumps by several persons as a group is simulated without need for a fall simulator of large dimensions which also prevents the risks associated with the concurrent jumps of several persons in the same blower vein.

In a particular mode of realization, other devices 7 are associated to the free-fall simulator, for example means 71 for the access to the aerodynamic vein 2, a zone 72 for the preparation of the persons to the simulated fall, means 73 to make the public wait for the simulated fall. 

1- A simulator of free-fall, to create a state of simulated free-fall for at least a person (6), containing air power generators (1), an aerodynamic vein (2) of vertical axis appreciably cylindrical or slightly conical in which evolves at least a person in state of free-fall and a stiff structure to secure the aerodynamic vein (2) characterized such that the aerodynamic vein (2) is bounded laterally by a wall (24) of inelastic flexible material maintained in tension between a lower stiff frame (28) and an upper stiff frame (29), where the stiff holding structure is a superstructure (5) containing the stiff elements (51), the aforementioned stiff elements being horizontally away from the wall (24) at a distance at least of the order of size of the diameter of the aerodynamic vein (2) so that the person in state of free-fall cannot be projected, during the operation of the simulator, against the said stiff elements due to the deformation of the wall (24) of flexible material or the said person passing through the aforementioned wall and where the lower and upper frames are maintained in positions relative to each other by means of the aforementioned superstructure. 2- The simulator of free-fall as per claim 1 where the wall (24) of the aerodynamic vein (2) is made of a single deployable panel of a film of non-elastic flexible material wrapped on itself by means of a line of fixations (27) on the two opposite edges of the aforementioned panel to establish the aerodynamic vein (2). 3- The simulator of free-fall as per claim 1 in which the lower stiff frame (28) and\or the upper stiff frame (29) are fixed to stiff elements (51) of the superstructure (5) by elastic devices under tension. 4- The simulator of free-fall as per claim 1 in which the air power generators (1) contain at least one engine (10) in a chamber (12), at least one helix (11) and a rectifier-diffuser (19) at the top of the chamber (12). 5- The simulator as per claim 4 in which the superstructure (5) is positioned with regard to the chamber (12) containing at least one engine (10) such as to maintain the aerodynamic vein (2) above and appreciably in the axis of the rectifier-diffuser (19). 6- The simulator as per claim 4 in which the chamber (12) contains at least one opening (17) capable of admitting the air (18) necessary for the operation of the aerodynamic vein (2) in the chamber (12) containing at least one engine (10); 7- The simulator as per claim 4 in which the chamber (12), the at least one engine (10), the at least one helix (11) and the rectifier-diffuser (19) are assembled in all or part of a container (74) suitable for transportation. 8- A simulator of free-fall as per claim 1 containing means of projection (3) to display images on the wall (24) of the aerodynamic vein (2), the aforementioned means (3) containing projectors (31) placed outside of the aforementioned aerodynamic vein (2) between the stiff structure of maintain of the aerodynamic vein (2) and the wall (24) of the aforementioned vein, and in which the film of flexible material constituting the wall (24) of the aerodynamic vein (2) is translucent so that images projected on the outside face (35) of the wall (24) around of the vein (2) are visible from inside the vein (2) on the inner side (36) of the wall (24) of the aforementioned vein (2). 9- The simulator of free-fall as per claim 8 in which projectors (31) are fixed to stiff elements (51) of the superstructure (5) of maintain of the aerodynamic vein (2). 10- The simulator of free-fall as per claim 8 in which the means of projection (3) generate a visual environment in the aerodynamic vein (2) over 360 degrees in a horizontal plane. 11- The simulator of free-fall as per claim 8 in which the means of projection (3) receive the images corresponding to at least another person in state of free-fall simulated in at least another simulator of free-fall, the aforementioned images being inserted in real time within the projected images. 12- The simulator of free-fall as per claim 1 in which the superstructure (5) maintains around the aerodynamic vein (2) means of protection (53) from the environment outside the simulator of fall. 13- The simulator of free-fall as per claim 12 in which the means of protection (53) create around the aerodynamic vein (2), inside the aforementioned means of protection (53), conditions of reduced luminosity compatible with the luminosity of the images projected on the wall (24) of the aerodynamic vein (2). 14- The simulator of free-fall as per claim 12 in which the means of protection (53) protect at least a zone (4) isolated from the aerodynamic vein (2) for a post of control and of command (41) of the simulator of fall. 15- The simulator of fall as per claim 12 in which the means of protection (53) consist at least partially of an appreciably opaque canvas stretched out over the superstructure (5). 